Metallic seal

ABSTRACT

The present invention is directed to a resilient, annular, metallic seal member having a generally “j” shaped cross-section. The annular, metallic seal member includes a first end portion having a first distal end, a generally curled second end portion that extends to a second distal end, and a central body portion between and contiguous with the first and second end portions. The annular, metallic seal member has a first side and an opposite second side. The second end portion curls in a first direction in accordance with a predetermined radius such that the second distal end is located across from the first side of the annular, metallic seal member and the first and second distal ends do not face each other.

BACKGROUND OF THE INVENTION

The present invention relates to a metallic seal for the containment ofhigh pressure fluids, including gases, from cryogenic to highly elevatedtemperatures. More particularly, the present invention relates topressure-energized, annular metallic lip seals with lateral offset,angular and axial misalignment capability.

In the field of fluid containment of high pressure fluids, resilientmetallic seals are employed in applications where elastomeric andpolymeric materials cannot be used because of extremely high pressures,high temperatures and/or aggressive media. Such sealing devices areproduced in different configurations designed to meet a variety ofoperating requirements.

One such seal is the “Axial C-Seal”, a partial cross-section of which isshown in FIG. 1 which was developed as an improvement in flexibilityover the hollow metal o-ring. Like the metal o-ring, the axial c-sealmay be used to seal gaps between cylindrical surfaces, in mainly staticapplications.

Other seals have been developed to perform this function, for example,those shown in the following U.S. Pat. Nos.: 4,457,523; 4,854,600;5,799,954; 6,257,594; and 6,446,978. All of these seals serve theirpurpose, but have limitations when required to be bothpressure-energized and capable of accommodating significantmisalignments of the cylindrical surfaces to be sealed.

In devices known as couplings, a rigid hollow proboscis or probe isinserted into a hollow receptacle in a fluid transmission system. Thereceptacle contains a sealing ring or multiple sealing rings, which aredilated by the inserted probe, thereby creating the required contactstresses to achieve fluid containment between the two bodies to besealed together.

C-seals are presently employed in couplings. Occasionally, due toimperfect field installation practices, the probe will be forced intothe receptacle before the centerlines or axes of the two components areproperly aligned. When this occurs, the probe may dent one side of thec-seal, which may not be sufficiently resilient to elastically deform,and therefore may leave a gap on the opposite side which results inleakage of fluid when the joint is pressurized.

It is highly desirable to provide an improved metallic seal whichovercomes the foregoing problems.

SUMMARY OF THE INVENTION

In accordance with the present invention it has now been found that ametallic seal has been provided which obtains the foregoing objectives.

The metallic seal of the present invention has a C-shaped portion whichconnects to a longitudinally extending portion. The c-shaped portiondesirably has a discrete radius with a smaller radius than the axialc-seal, to prevent contact between the probe and this relatively rigidarea during installation. The inside diameter of the c-shaped portion isdesirably extended axially towards the end of the c-shaped portion andtowards a first end of the seal, and slightly inwardly, desirablyterminating in a small inwardly curled portion forming a lip. Theopposed portion of the c-shaped portion connects to a longitudinallyextending portion which extends above or beyond the c-shaped portion andwhich desirably terminates in a small outwardly curved portion. Theoverall configuration of the seal is somewhat L-shaped, or J-shaped.

Further features and advantages of the present invention will appearhereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more readily understandable from aconsideration of the accompanying drawings, wherein:

FIG. 1 is an enlarged cross-sectional view of a prior art axial c-seal;

FIG. 2 is an enlarged cross-sectional view of one embodiment of the sealof the present invention;

FIG. 3 is an enlarged side view of a further embodiment of the seal ofthe present invention;

FIG. 4 is an enlarged schematic cross-sectional view of the installationof the seal of the present invention;

FIG. 5 is an enlarged schematic cross-sectional view of a seal of thepresent invention installed, with the axis of the probe displaced to theright;

FIG. 6 is an enlarged schematic cross-sectional view of an installedseal of the present invention with the axis of the probe displaced tothe left; and

FIG. 7 is an enlarged schematic cross-sectional view of an installedseal of the present invention at operating pressure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to the drawings in detail, FIG. 1 shows an enlarged endview of a prior art axial c-seal 10, showing an arcuate portion 12,outer sealing line 14 and inner sealing line 16.

FIG. 2 shows an enlarged end view of one embodiment of a seal 20 of thepresent invention showing an arcuate portion 22, outer sealing line 24and inner sealing line 26. In addition, the seal 20 of FIG. 2 includesan inward curl 28 at one end of the arcuate portion which forms a return29 at a first edge 30 of seal 20, and the opposed end of the arcuateportion connects to an inwardly tapering frustro-conical portion orlongitudinally extended portion 32 which terminates in an outward curvedportion 34 to the second opposed edge 36 of seal 20. The function of thereturn is to provide stiffening and a lead-in which facilitates assemblyfor the smooth insertion of the seal into the external cavity duringinstallation.

FIG. 3 shows an enlarged side view of a seal 40 of the present inventionshowing the arcuate portion 42, an inwardly tapered frustro-conicalportion 44, inward curl 46 and outward curl 48. A first portion 50 isconnected to a second portion 52 of seal 40 by longitudinally extendingbody portion 54, which depicts a preferred longitudinally extending bodyof the seals of the present invention. The embodiment of the seal shownin FIG. 3 includes a material taper 56 at the frustro-conical portion 44wherein the thickness of the material forming the seal decreases toincrease the flexibility of the seal.

The preferred materials for the seals of the present invention includenickel super alloys and nickel cobalt alloys, although other metals maybe used.

The seals of the present invention have several significant advantages.Thus the flexibility of the inward facing lip 29 is enhanced byincreased distance from the more rigid c-shaped part of the section andit can be deflected radially by a lower force.

In addition, the configuration of the frustro-conical portion 44 may bereshaped by deflecting relatively easily to accommodate an off-centerprobe without plastic deformation of this region.

Still further, the seal of the present invention may be manufacturedfrom a thicker material stock from that of the prior art axial-c-seal ifdesired without an appreciable increase in insertion force or gallingtendencies.

In addition, greater material thickness and a close proximity betweenthe installed probe and the deflected inner frustro-conical leg of thering cross-section enables higher operating and proof pressures to besustained without gross permanent deformation.

Also, the seals of the present invention have enhanced reliability.Multiple insertions of the probe into the seals have been a problem forprior art seals.

A further advantage of the seals of the present invention is a taperedcross-section of the frustro-conical portion. This even more flexiblefeature is advantageous for dynamic, sliding applications, albeit atslow speeds because of reduction of contact stresses.

FIG. 4 is an enlarged, schematic side view of the installation of theseals of the present invention showing the insertion of a seal of thepresent invention in the body of a coupling. FIG. 4 shows seal 60installed in body 62 of a coupling, with retaining wall 64 positionedadjacent the seal and probe 66 spaced from the seal. FIG. 5 shows analternate seal 70 having an outward curved portion 72 andfrustro-conical portion 74. The seal 70 is installed in an interferencerelationship with body 62 and axial retaining wall 64, with probe 66inserted in contacting, interfering relationship with the seal adjacentto the frustro-conical portion. Elastic deflection of the seal inner lipand tapered frustro-conical portion permits lateral offset of the probewithout leakage. In FIG. 5 the axis of probe 66 is displaced to theright vis-a-vis body 62; whereas the embodiment of FIG. 6 shows arelationship similar to FIG. 5 and depicts the axis of the probedisplaced to the left vis-a-vis body 62, widening the gap between body62 and the frustro-conical portion 74.

FIG. 7 shows an enlarged schematic side view similar to FIG. 5 of aninstalled seal 60 at an exemplificative high operating pressure of30,000 psi deflecting the walls of the seal wherein the seal 60 is notcompletely deformed. The darker areas 80 on the body 62, retaining wall64 and probe 66 show higher stress contact regions.

Naturally, variations in the seal are contemplated. For example, thelongitudinally extending portion could be conical or have a slightcurve. The c-shaped portion could have variations and flats and need notbe uniform. All shapes could be slightly irregular.

Various coatings, including silver or gold, may be beneficially appliedto the seal or its contact surfaces in order to improve its sealingefficiency. For dynamic applications special anti-galling, low-frictioncoatings may be applied. Thus, sealing contact areas may be coated withsoft, lubricious and/or anti-galling materials.

It is to be understood that the invention is not limited to theillustrations described and shown herein, which are deemed to be merelyillustrative of the best modes of carrying out the invention, and whichare susceptible of modification of form, size, arrangement of parts anddetails of operation. The invention rather is intended to encompass allsuch modifications which are within its spirit and scope as defined bythe claims.

1-9. (cancelled)
 10. An annular seal member having a generally “j”shaped cross-section and comprising a first end portion having a firstdistal end, a generally curled second end portion that extends to asecond distal end, and a central body portion between and contiguouswith said first and said second end portions, said annular sealingmember having a first side and an opposite second side, said second endportion curling in a first direction in accordance with a predeterminedradius such that said second distal end is located across from saidfirst side of said seal member and said first and second distal ends donot face each other.
 11. The annular seal member according to claim 10wherein the portion of the first end portion having said first distalend is slightly angulated in said first direction.
 12. The annular sealmember according to claim 10 wherein said central body portion has agenerally frustro-conical shape and has no inflection points.
 13. Theannular seal member according to claim 10 wherein said annular sealmember is metallic.
 14. The annular seal member according to claim 13wherein said annular seal member is fabricated from a metal chosen fromthe group consisting of nickel super alloys and nickel cobalt alloys.15. The annular seal member according to claim 10 wherein said annularseal member has a degree of resiliency.
 16. The annular seal memberaccording to claim 10 wherein said central body portion has a thicknessthat tapers in the direction of said first distal end.
 17. An annularseal member comprising: a first side and an opposite second side; agenerally frustro-conical central body portion having opposite ends; afirst end portion contiguous with one of said opposite ends of saidgenerally frustro-conical central body portion, said first end portionhaving a first distal end; a generally curled second end portioncontiguous with the other of said opposite ends of said generallyfrustro-conical central body portion, said second end portion extendingto a second distal end; and said second end portion curling in a firstdirection in accordance with a predetermined radius such that saidsecond distal end is located across from said first side of said annularseal member and said first and second distal ends do not face eachother.
 18. The annular seal member according to claim 17 wherein theportion of said first end portion having said first distal end isslightly angulated in said first direction.
 19. The annular seal memberaccording to claim 17 wherein said annular seal member is metallic. 20.The annular seal member according to claim 19 wherein said annular sealmember is fabricated from a metal chosen from the group consisting ofnickel super alloys and nickel cobalt alloys.
 21. The annular sealmember according to claim 17 wherein said annular seal member has adegree of resiliency.
 22. The annular seal member according to claim 17wherein said generally frustro-conical central body portion has athickness that tapers in the direction of said first distal end.
 23. Anannular seal member having a generally hook shaped cross-section, afirst side and a second opposite side, said annular seal membercomprising a first end portion having a first distal end, a generallycurled second end portion that extends to a second distal end, and acentral body portion between and contiguous with said first and said endportions, said second portion curling in a first direction in accordancewith a predetermined radius such that said second distal end is locatedacross from said first side of said annular seal member and said firstand second distal ends do not face each other.
 24. The annular sealmember according to claim 23 wherein the portion of said first endportion having said first distal end is slightly angulated in said firstdirection.
 25. The annular seal member according to claim 23 whereinsaid central body portion has a generally frustro-conical shape.
 26. Theannular seal member according to claim 23 wherein said annular sealmember is metallic.
 27. The annular seal member according to claim 26wherein said annular seal member is fabricated from a metal chosen fromthe group consisting of nickel super alloys and nickel cobalt alloys.28. The annular seal member according to claim 23 wherein said annularseal member has a degree of resiliency.
 29. The annular seal memberaccording to claim 23 wherein said central body portion has a thicknessthat tapers in the direction of said first distal end.
 30. An annularmetallic seal comprising: a first side and an opposite second side; agenerally frustro-conical central body portion having opposite ends; afirst end portion contiguous with one of said opposite ends of saidgenerally frustro-conical central body portion, said first end portionhaving a first distal end; a curled second end portion contiguous withthe other of said opposite ends of said generally frustro-conicalcentral body portion, said second end portion extending to a seconddistal end; said generally frustro-conical central body having athickness that tapers in the direction of said first distal end; saidthe first distal end being slightly angulated a first direction; andsaid second end portion curling in said first direction in accordancewith a predetermined radius such that said second distal end is locatedacross from said first side of said annular metallic seal and said firstand second distal ends do not face each other.